A Wittig Reaction with 2-Furyl Substituents at the Phosphorus Atom: Improved (Z) Selectivity and Isolation of a Stable Oxaphosphetane Intermediate
作者:Marco Appel、Steffen Blaurock、Stefan Berger
DOI:10.1002/1099-0690(200204)2002:7<1143::aid-ejoc1143>3.0.co;2-g
日期:2002.4
Wittig reactions with ylides bearing one, two or three 2-furyl groups directly bound to the phosphorus atom have been studied. Greatly improved (Z)-alkene selectivities of up to 98:2 could be observed if 2-furyl groups were present. Monitoring of the reactions by NMR spectroscopy revealed only oxaphosphetane intermediates, which became more stable with increasing number of 2-furyl substituents bound
已经研究了与带有一个、两个或三个直接与磷原子结合的 2-呋喃基的叶立德的 Wittig 反应。如果存在 2-呋喃基,则可以观察到高达 98:2 的 (Z)-烯烃选择性大大提高。通过 NMR 光谱对反应的监测显示只有氧代膦烷中间体,随着与磷原子结合的 2-呋喃基取代基数量的增加,中间体变得更加稳定。Oxaphosphetane 10d 与三个呋喃基团被成功分离,并提供了晶体结构分析的结果。(© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)